Blow Molded Container

ABSTRACT

The present invention is directed to a container comprising a retention mechanism for attaching a closure to an opening or neck of a container with a portion of the container body comprising a physical geometry that creates more than one undercut.

CROSS REFERENCE TO RELATED APPLICATION

The application claims priority to U.S. Provisional Application Ser. No.61/433,062, filed on Jan. 14, 2011; and U.S. Provisional ApplicationSer. No. 61/433,052, filed on Jan. 14, 2011; and U.S. ProvisionalApplication Ser. No. 61/433,068, filed on Jan. 14, 2011; and U.S.Provisional Application Ser. No. 61/433,072, filed on Jan. 14, 2011; andU.S. Provisional Application Ser. No. 61/433,079, filed on Jan. 14,2011; and U.S. Provisional Application Ser. No. 61/432,698, filed onJan. 14, 2011, all of which are herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a blow-molded container with aretention mechanism for attaching a closure to an opening or neck ofsaid container and a portion of said container comprising a physicalgeometry that creates more than one undercut.

BACKGROUND OF THE INVENTION

A variety of packages, including dispensing packages or containers, havebeen developed for household products, personal care products, and otherproducts. Containers that have a pleasing aesthetic look to consumershave a closure design that is fully integrated with the design of thecontainer. This conveys the message that the integration of the twocomponents was well thought of. This is important to make closurefunctioning intuitive to consumers. An example of a well integratedcontainer/closure system is one where the container's geometry wrapsaround the closure to create shoulders. This geometry can also bereferred to as a container with a recessed neck. This recess geometryserves different purposes: overall integrated look to the container andclosure, stability to container in inverted orientation, and makesfunctioning of closure more intuitive to consumers.

Blowing this container geometry with today's traditional blow moldingtechnology, is not possible, as the container would have undercuts inthe concave portion of the shoulder. This is because when the moldingcavity tools are to be opened, the steel creating the concave partbecomes trapped. If one were to shape the top part using the blow pinhead tool, one would then encounter an undercut under the snap beadfeature that is in proximity to the container's shoulder. This isbecause one would not be able to pull the blow pin tooling which createsthe snap bead from underneath the formed bead feature.

When looking at containers in the market that use a recess geometrydesign, it has been noticed that they usually have a straight shouldervs. a concave design. The forming of that recess does not require anyinventive step as there is at least one direction in which the mold canopen with a straight-pull motion without yielding to any mold materialbecoming trapped within the container's geometry. Yet, recess geometriesthat can be unmolded with a straight-pull in a blow mold are highlyrestricted in design, limiting the integration of the closure with theblown container and therefore all the benefits stated above.

There are other containers currently in the market that have differentshoulder geometries, but these containers use a different neck from whatthe present invention has found. These containers use a closureattachment mechanism, where the closure snaps onto the container fromthe inside of the dispensing orifice. A non-limiting example of acontainer made through the process described in the present inventioncan be referred to as having a snap-on closure mechanism, which snapsonto the outside of the container's neck. From the present inventiondiscovery, the present design provides more reliability against leaking,as the outside part of the neck is calibrated, providing tightertolerances, than the inside part of the container. The inside of thecontainer is not highly calibrated, increasing the probability of poorengagement between container and closure, and thus leading to potentialleaking. This is because the parts blown via the extrusion blow moldingprocess usually have better controlled geometry on the outside of thepart rather than the inside, as the material wall thickness can vary dueto part aspect ratios translating into differing parison stretch ratiosin both radial and axial directions. In addition, containers whoseclosures attach onto the container from the inside of the neck usuallyrequire trimming and reaming of the neck as secondary operations. Anoperation that cuts-away excess material is inherently notcost-effective and should be avoided. Furthermore, any cutting operationrequires straight access to the part that shall be cut away restrictingthe available recess geometry and limiting the integration of theclosure with the blown container and therefore all the benefits statedabove. With a closure attachment mechanism where the closure seals fromthe inside of the neck and snaps onto the container from the outside ofthe neck, a traditional striker plate and blow pin tool design can beused, where the blow pin cuts the parison when it comes in contact withthe striker plate, creating a calibrated neck and therefore eliminatingthe need for secondary operations such as trimming and reaming.

Currently, most closures complete the geometry of the container, therebyrequiring the size of the closure to be proportional to the geometry ofthe container. In the present invention, the size of the closure isminimized thereby providing several benefits. One of the benefits isreducing the weight of the closure to the minimum amount of resin neededto enable the required closure functionality. This is a benefit for theenvironment as industry currently does not have a well establishedpolypropylene recycling stream. By having a closure that has a reducedweight from the overall package, this allows a container to haveimproved recyclability. It also reduces the overall costs of the closureincluding costs associated with resin, processing, tooling, injectionmold (IM) press selection, and others. Another benefit of minimizingclosure size is that the closure becomes a less focal point of thedesign making it more inductive to use the same closure for differentcontainer designs within one brand and even enable the use of the sameclosure across different brands/shaped families. This drivesoptimization and efficiency and in return reduces further costs. Thisfurther enables the silhouette of the shape to be scaled proportionallywithout the use of additional features such as steps, larger radii orother geometric alterations and angles to accommodate the closure.

Another benefit for minimizing the closure size is that it can beintegrated in the container shape. When the container is in its invertedorientation, an integrated design allows the use of the container topsurface to add stability vs. requiring a larger closure. It also aids increating differentiation between the forms (such as shampoo andconditioner), helping consumers identify the product that they arelooking for. This drives scale in the container design and developmentand therefore is an advantage. A further advantage is that having arecessed closure provides a higher level of protection from damage dueto the recessed closure being protected by the recess geometry. Anotherbenefit of having a recessed neck where the container wraps around theclosure is that it enables using the same closure across different sizeswhile still having an integrated look between the container and theclosure. A further benefit of the present invention is the enablement ofusing the same closure across containers made by different moldingtechnologies. Non-limiting examples of molding technologies includeextrusion blow molding (EBM), injection blow molding (IBM), andinjection stretch blow molding (ISBM). This drives scale and furtherreduces costs.

It is an objective of the present invention to describe a blowncontainer, wherein said container contains a recess in the container'sgeometry. Such a recess allows integration of a closure with thecontainer such that when the closure is coupled with the blowncontainer, it is substantially flush to the apex of the outmost surfaceof that blown container.

SUMMARY OF THE INVENTION

The present invention is directed towards a blow molded containercomprising a physical geometry that creates more than one undercut,preferably a recess, and a closure retention mechanism for attaching aclosure to an opening or neck of said container.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an isometric view of a final container shape with a recessedneck and a snap bead closure attachment mechanism;

FIG. 1B is an isometric view of a non-limiting example of a miniatureclosure;

FIG. 1C is a container with a recessed neck and a miniature closureassembled and standing in an up-right and an upside-down orientations;

FIG. 1D is a top view of a container illustrating the molding partingline and directions of mold action.

FIG. 1E is a top view of a container with a recessed neck and aminiature closure assembled.

DETAILED DESCRIPTION OF THE INVENTION

For the purposes of the present invention, suitable recesses are thosethat permit a portion of the article to wrap around at least part of aclosure, when said closure is coupled with said article. Such recess mayallow the closure, when coupled to said article, to remain substantiallyflush to the apex of the outermost surface of said article. By “at leastpart of a closure” it is herein intended that said portion extendsaround the perimeter of the closure to form an angle of at least 45°,preferably at least 60°, more preferable between 60° and 360°, takenfrom the centre of the closure and in the x-y plane, when said closureis coupled to said article.

The term “integrated” as used herein intends that: (i) at least part ofsaid closure remains substantially flush with at least one surface ofthe article, preferably the outer surface of said shoulder; and (ii)that at least one shoulder of said article wraps around at least part ofsaid closure, preferably forming at least one concave surface. Theadvantage of such configuration being a consumer desirable silhouette.

The term “undercut” as used herein means a physical geometry thathinders article removal from a mold when said mold is opened in a lineardirection which intersects at least a portion of said geometry.

The term “without damage” as used herein means that the article retainsthe end physical geometry generated at the end of the molding process.

The term “scale” as used herein refers to an economic benefit obtainedby reducing the design and development time and resources, as well ascapital investment obtained by direct reapplication without negativeimplications on consumer acceptance, design aesthetics, etc.

Blow molding is a well known manufacturing process for the fabricationof plastic articles such as containers, fuel tanks, handles etc. Theblow molding process begins with melting plastic and forming it into aparison or preform. The parison is then clamped into a mold and apressurized medium, usually air, is blown or pumped into it. The airpressure forces the plastic to match the peripheral geometry of themold. Once the plastic has cooled and hardened the mold opens and thepart is ejected.

There are three main types of blow molding platforms: extrusion blowmolding (EBM), injection blow molding (IBM) and stretch blow molding(SBM). In some applications the combination of the abovementioned blowmolding platforms may be more appropriate depending on the propertiesand complexity of the articles to be formed, such as injection stretchblow molding (ISBM).

Plastic resin materials for use in the present invention can bepolyolefins such as polyethylene (PE) and polypropylene (PP),polystyrene (PS), polyvinyl chloride (PVC), polylactic acid (PLA) orpolyethylene terephthalate (PET).

As used herein and unless otherwise stated, “polyethylene” encompasseshigh density polyethylene (HDPE), low density polyethylene (LDPE),linear low density polyethylene (LLDPE), and ultra low densitypolyethylene (ULDPE). As used herein and unless otherwise stated,“polypropylene” encompasses homopolymer polypropylene, random copolymerpolypropylene, and block copolymer polypropylene.

Therefore, there is a need for a new container design that has arecessed neck (102) and a closure retention mechanism (103). Thecontainer (101) can be made via any of the different blow moldingprocesses previously described.

In an embodiment of the present invention, a container (101) comprises aclosure retention mechanism (103) for attaching a closure (106) to anopening or neck (102) of a container (101) that can be selected from thenon-limiting group consisting of snap bead, thread, bayonet, andmixtures thereof.

In an embodiment of the present invention, a container (101) alsocomprises a geometry shape that would traditionally be considered tocreate more than one undercut (107) and therefore removing the containerfrom the mold after molding it would become challenging withouttemporarily or permanently altering or deforming the shape of thecontainer. This is because the material of the mold used to create theshape of the container would become trapped within the container'sgeometry, not allowing for a straight pull opening action of the mold,as shown in FIG. 1D.

In an embodiment of the present invention, a container (101) comprises ageometry where the interface (105) between the closure (106) and thecontainer's geometry about the neck of the container can be selectedfrom the non-limiting group consisting of concave, convex, linear,non-linear, or mixtures thereof. The specific shape of the interfacegeometry (105) can be defined to match the shape of the closure (106),allowing therefore the creation of an integrated look between theclosure (106) and the container (101).

In a further embodiment of the present invention, a container (101)comprises a non-linear geometry about a neck of the container andclosure interface of the container. The curvature of the interface (105)allows having the container wrap around the closure (106) to enable afully integrated desired design aesthetic. The portion of the container(101) that wraps around the closure (106) can be referred to as thecontainer's shoulder (104).

In an embodiment of the present invention, a container (101) comprises ashoulder (104) geometry where the side of the shoulder wall having aninterface (105) with the closure (106) has a positive draft angle ofless than 10 degrees and in a further embodiment, there may be furtherreduction of the draft angle to less than 8 degrees and preferably evena further reduction of the draft angle to 5 degrees or less. Thisshoulder surface creates the interface (105) between the container (101)and the closure (106), once the closure (106) is assembled. Having apositive draft angle of less than 10 degrees is important for two mainreasons:

-   -   1) Consumer acceptance—the smaller the draft angle, the smaller        the space or gap (108) that will exist between the closure (106)        and container (101) after the closure (106) is assembled. Large        gaps are typically perceived by consumers as areas where water        and product can accumulate, making the overall assembly be        perceived as messy. In addition, a large gap can give consumers        the perception that the closure and container are not fully        integrated, making the overall package appear as a poor design.        When such a gap (108) exceeds 7.4 mm distance from the shoulder        surface (104) to the closure (106), the consumer also perceives        an internal barrier for product flow.    -   2) Potential re-application of closure (106) across multiple        container sizes—having a low draft angle on the container's        vertical shoulder interface (105) wall enables using a closure        (106) with a straight or low vertical draft angle. If the        closure (106) has a low vertical draft angle, it can then be        used not only with containers that have a shoulder (104) that        cover this side of the closure, but also with containers that        have a different shoulder design or even those that do not have        a shoulder at all, where the closure's periphery is partially or        fully exposed. Having the flexibility to use the same closure        across different container designs creates scale, which        typically reduces costs and logistic complexity.

In an embodiment of the present invention, a container (101) comprises ashoulder (104) geometry wherein the shape of the shoulder can bemodified to mold containers of different volumetric sizes, while stillbeing able to couple them with the same closure (106). Modifying theshape of the shoulder (104) to match with the same closure (106) createsscale which typically reduces costs, while allowing the overall assemblyto maintain its fully integrated aesthetic look.

In a further embodiment of the present invention, a portion of acontainer body may have a physical geometry that creates at least onenon-linear or more than one linear undercut. In an embodiment, a linearundercut may have a portion of the surface geometry such that thesurface is within the same plane. In an embodiment of the presentinvention, a non-linear undercut can be defined by a portion of thesurface geometry such that the surface exists in multiple planes.

In an embodiment of the present invention, a container (101) is made bya process selected from the non-limiting group consisting of extrusionblow molding (EBM), injection blow molding (IBM), injection stretch blowmolding (ISBM) or mixtures thereof.

In an embodiment of the present invention, a container (101) comprises ashoulder (104) geometry that is integrated with a closure (106) andpreferably the integration of this shoulder (104) geometry with thisclosure (106) completes a container silhouette.

In an embodiment of the present invention, a container (100) wherein theneck of the container may be at least partially encompassed by a portionof a container body.

In an embodiment of the present invention, a container (101) comprises aclosure retention feature (103) wherein the container's retentionfeature (103) can be referred to as a “male component”, as it protrudesfrom the container's outer neck finish, whilst the closure (106)comprises the “female component”, as it has a recessed area into whichthe container (101) will fit once assembled. In an embodiment of thepresent invention, a container (101)

In an embodiment of the present invention, a container (101) comprises aclosure retention feature (103) wherein the container's retentionfeature (103) has a depth of less than about 1.5 mm from a tip of a beadto a base or outer diameter of a neck. Having this depth is important asit ensures that there will be enough engagement between the closure(106) and the container (101) to prevent the unintentional detachment ofthe closure from the container. In a different embodiment of the presentinvention, a container comprises a closure retention feature wherein thecontainer's retention feature can be referred to as a “femalecomponent”, as it has a recession from the container's outer neckfinish. The closure's retention feature can be referred to as a “malecomponent”, as it protrudes from the closure's finish and fits into thecontainer once assembled. In an embodiment of the present invention, acontainer comprises a closure retention feature wherein the container'sretention feature has a depth of less than about 1.5 mm from an outerdiameter of a neck to the base of the female retention feature. Havingthis depth is important as it ensures that there will be enoughengagement between the closure and the container to prevent theunintentional detachment of the closure from the container.

In a different embodiment of the present invention, a container (101) iscomprised of a material selected from the non-limiting group consistingof polyolefins such as polyethylene (PE) and polypropylene (PP),polystyrene (PS), polyvinyl chloride (PVC), polylactic acid (PLA),polyethylene terephthalate (PET), or mixtures thereof. These are typicalresins used in the manufacturing of blow molded containers. In oneembodiment, the plastic resin material is the polyolefin high densitypolyethylene (HDPE). The plastic materials may be made frompetrochemical-sourced monomers or bio-sourced monomers.

In a further embodiment of the present invention, a container (101)comprises two standing surfaces (109) in container geometry. With thisgeometry, the molded article can be placed in multiple orientations,such as upright or inverted orientation. This geometry further providesfor a non-protruding closure (106) for the molded article.

In an embodiment of the present invention, a container (101) is removedfrom the molding cavity without permanently or temporarily deforming themolded container features. This is important because any type ofdeformation, being permanent or temporary, can lead to affecting thefeature's integrity.

In an embodiment of the present invention, a container (101) iscomprised of a biodegradable polymer or mixture of biodegradablepolymers.

In a further embodiment of the present invention, a container (101) iscomprised of a biodegradable polymer material selected from thenon-limiting group consisting of polylactic acid (PLA), polyglycolicacid (PGA), polybutylene succinate (PBS), an aliphatic-aromaticcopolyester based on terephthalic acid, an aromatic copolyester with ahigh terephthalic acid content, polyhydroxyalkanoate (PHA),thermoplastic starch (TPS), cellulose, or a mixture thereof.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm”.

All documents cited in the Detailed Description of the Invention are, inrelevant part, incorporated herein by reference; the citation of anydocument is not to be construed as an admission that it is prior artwith respect to the present invention. To the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

1) A container comprising: a) a retention mechanism for attaching aclosure to an opening or neck of a container; b) a portion of acontainer body comprising a physical geometry that creates more than oneundercut. 2) A container according to claim 1 wherein the portion of thecontainer comprises a geometry of the container about a neck of acontainer and a closure interface of the container which is selectedfrom the group consisting of concave, convex, linear, non-linear,mixtures of linear and non-linear, or mixtures thereof. 3) A containeraccording to claim 2 wherein the portion of the container comprises anon-linear geometry about a neck of the container and a closureinterface of the container. 4) A container according to claim 1 whereinthe container comprises a geometry wherein the vertical side of theshoulder that has an interface with a closure has a positive draft angleof less than 10 degrees. 5) A container according to claim 1 wherein theneck of the container is at least partially encompassed by a portion ofa container body. 6) A container according to claim 1 wherein theshoulder geometry can be modified and molded to use a same closureacross different volumetric sized containers. 7) A container accordingto claim 1 wherein the container is made by a process selected from thegroup consisting of extrusion blow molding, injection blow molding,injection stretch blow molding and mixtures thereof. 8) A containeraccording to claim 1 wherein the shoulder geometry is integrated with aclosure. 9) A container according to claim 1 wherein the retentionfeature is a male component in an interface or attachment of a closure.10) A container according to claim 9 wherein the retention feature has adepth of less than about 1.5 mm from a tip of the bead to a base orouter diameter of a neck. 11) A container according to claim 1 whereinthe retention feature is a female component in an interface orattachment of a closure. 12) A container according to claim 11 whereinthe retention feature has a depth of less than about 1.5 mm from anouter diameter of the neck to the base of the female retention feature.13) A container according to claim 1 wherein the container is comprisedof a material selected from the group consisting of polyolefins such aspolyethylene (PE) and polypropylene (PP), polystyrene (PS), polyvinylchloride (PVC), polylactic acid (PLA), polyethylene terephthalate (PET),or mixtures thereof. 14) A container according to claim 1 wherein thecontainer comprises two standing surfaces in a container geometry. 15) Acontainer according to claim 1 wherein features of the container are notdeformed temporarily or permanently during removal from the moldingcavity. 16) A container, manufactured by the process described in claim7, which is composed of biodegradable polymers. 17) A container,manufactured by the process described in claim 16, wherein thebiodegradable polymer is selected from the group consisting ofpolylactic acid (PLA), polyglycolic acid (PGA), polybutylene succinate(PBS), an aliphatic-aromatic copolyester based on terephthalic acid, anaromatic copolyester with a high terephthalic acid content,polyhydroxyalkanoate (PHA), thermoplastic starch (TPS), cellulose, or amixture thereof.